Load reduction based on percentage change in energy price

ABSTRACT

A thermostatic controller is configured for curtailing load when energy price rate is high. One or more energy price rates received by a receiver device are stored in an electronic memory. A microprocessor is operable to select from the one or more energy price rates the lowest energy price rate received within a given time period for establishing a base energy price rate. The microprocessor is operable to determine if the energy price rate for a present time period exceeds the base energy price rate by more than a first percentage or multiplier factor of the base energy price rate. In response to an energy price rate that exceeds the base energy price rate by more than the first percentage or multiplier factor, the microprocessor is configured to select a first temperature offset corresponding to the first percentage or multiplier factor and change the set point temperature by the first temperature offset.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 12/766,155 filed on Apr. 23, 2010, which issues on Oct. 9, 2012as U.S. Pat. No. 8,285,419. The entire disclosure of the aboveapplication is incorporated herein by reference.

FIELD

The present disclosure relates to load reduction based on percentagechange in energy price, which may include thermostatic controllers forcontrolling the level of operation of one or more systems to correspondwith a time-of-use energy rate, and to thermostatic controllers that canprovide demand side management control to an electric utility provider.

BACKGROUND

This section provides background information related to the presentdisclosure which is not necessarily prior art.

As the demand for electrical power increases during the day, the utilityprovider experiences an increase in the cost of generating electricalpower as a result of secondary “peak” power plants that are switched onto supplement off-peak power generating plants. Many utility providersare consequently establishing real time energy price rates for chargingthe consumer a variable rate that increases as the cost of generatingpower increases during peak demand periods. These rates may vary basedon a utility price rate schedule, which establishes a different usageprice rate for a plurality of specified time periods of the day. Suchenergy price rates may also be periodically changed by a utilityprovider.

In situations where the peak demand begins to exceed the powergenerating capacity of the utility's off-peak and peak power plants, theutility may engage in demand side management by changing the price ratefor electrical power during peak demand periods, in an effort toencourage consumers to reduce energy usage to keep energy demand fromexceeding capacity. Utilities engaging in demand side managementtransmit a signal including information about an energy price rate in anattempt to encourage individuals to reduce the amount of energy usedduring peak demand periods.

In the example of an air conditioner controlled by a conventionalthermostat, the user would be billed at a higher rate when the airconditioner runs during peak energy demand periods. Previous attemptshave been made to provide a thermostat that receives a signal from autility provider and offsets the temperature setting during increaseddemand periods when energy costs are high, to reduce a consumer's energyusage. Such an offset would substantially raise the temperature settingand cause the air conditioner to immediately shut off and remain offuntil the temperature in the space rises above the significantly raisedtemperature setting. This would not only allow the utility to lowerenergy consumption to keep the peak demand from exceeding theircapacity, but also the user would be able to save on their energy bill.

But this method of offsetting a thermostat's temperature setting cannotalways be relied upon to reduce air conditioner operation and energyconsumption, because an occupant may still lower the temperature settingand override the offset. For example, if in response to a utility signalindicating an increase in price rate, a thermostat offset its 72°Fahrenheit temperature setting to 80° Fahrenheit and displayed indiciaof a high energy price rate, an occupant of the space may see the 80°set point and lower the setting back to 70° to override the offset. Inthis case, the utility would not succeed in curbing energy consumptionduring a peak demand period.

SUMMARY

This section provides a general summary of the disclosure, and is not acomprehensive disclosure of its full scope or all of its features.

An exemplary embodiment includes a thermostatic controller forcurtailing load of one or more energy consuming appliances when energyprice rate is high. The thermostatic controller generally includes areceiver device configured to receive a signal that includes an energyprice rate for a given time period. One or more energy price ratesreceived by the receiver device are stored in an electronic memorydevice. The thermostatic controller also includes a microprocessor incommunication with the receiver device and electronic memory. Themicroprocessor is configured to control operation of an energy consumingappliance to maintain a set point temperature. The microprocessorincludes a memory encoded with an instruction operable to select fromthe one or more energy price rates the lowest energy price rate receivedwithin a given time period for establishing a base energy price rate,and further encoded with an instruction operable to determine if theenergy price rate for a present time period exceeds the base energyprice rate by more than a first percentage or multiplier factor of thebase energy price rate. The microprocessor is configured to respond toan energy price rate that exceeds the base energy price rate by morethan the first percentage or multiplier factor by selecting a firsttemperature offset corresponding to the first percentage or multiplierfactor and changing the set point temperature by the first temperatureoffset.

Another exemplary embodiment includes a thermostatic controller forcurtailing load of one or more energy consuming appliances when energyprice rate is high. In this exemplary embodiment, the thermostaticcontroller generally includes a transceiver configured to receive asignal that includes an energy price rate for a given time period. Oneor more energy price rates received by the transceiver are stored in anelectronic memory. The thermostatic controller also includes amicroprocessor in communication with the transceiver and electronicmemory. The microprocessor is configured to select from the one or moreenergy price rates the lowest energy price rate received within a giventime period for establishing a base energy price rate, and to determineif the energy price rate for a present time period exceeds the baseenergy price rate by more than a first percentage or multiplier factorof the base energy price rate. The microprocessor is also configured torespond to an energy price rate that exceeds the base energy price rateby more than the first percentage or multiplier factor by transmitting asignal via the transceiver to an energy consuming appliance indicatingthat the energy consuming appliance should be in an off state.

In another exemplary embodiment, a thermostatic controller generallyincludes a transceiver configured to receive a signal that includes anenergy price rate for a given time period. One or more energy pricerates received by the transceiver are stored in an electronic memory. Amicroprocessor is in communication with the transceiver and electronicmemory. The microprocessor is configured to: select from the one or moreenergy price rates the lowest energy price rate received within a giventime period for establishing a base energy price rate; determine if theenergy price rate for a present time period exceeds the base energyprice rate by more than a first percentage or multiplier factor of thebase energy price rate; and respond to an energy price rate that exceedsthe base energy price rate by more than the first percentage ormultiplier factor by transmitting a signal via the transceiver to one ormore ceiling fans to activate, deactivate and/or change speed of the oneor more ceiling fans.

Additional embodiments include methods of using thermostatic controllersto curtail load when energy price rate is high. In an exemplaryembodiment, a method generally includes receiving a signal that includesan energy price rate for a given time period and storing one or moreenergy price rates in an electronic memory. The method also includesselecting a lowest energy price rate received within a given period oftime from the one or more energy price rates stored in the electronicmemory by using a microprocessor in communication with the electronicmemory, for establishing a base energy price rate. The method furtherincludes determining, using the microprocessor, if the energy price ratefor a present time period exceeds the base energy price rate by morethan a first percentage or multiplier factor of the base energy pricerate. Additionally, the method includes responding to an energy pricerate that exceeds the base energy price rate by more than the firstpercentage or multiplier factor by selecting, using the microprocessor,a first temperature offset corresponding to the first percentage ormultiplier factor and adjusting a set point temperature of an energyconsuming appliance by the first temperature offset to thereby reduceenergy consumption.

In another exemplary embodiment, a method generally includes receiving asignal that includes an energy price rate for a given time period;storing one or more energy price rates in an electronic memory; andselecting a lowest energy price rate received within a given period oftime from the one or more energy price rates stored in the electronicmemory by using a microprocessor in communication with the electronicmemory, for establishing a base energy price rate The method alsoincludes determining, using the microprocessor, if the energy price ratefor a present time period exceeds the base energy price rate by morethan a first percentage or multiplier factor of the base energy pricerate; and responding to an energy price rate that exceeds the baseenergy price rate by more than the first percentage or multiplier factorby transmitting a signal from the thermostatic controller to one or moreceiling fans to activate, deactivate, and/or change speed of the one ormore ceiling fans to thereby help reduce energy consumption.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1 is an illustration of a building incorporating a thermostataccording to the principles of the present disclosure;

FIG. 2 is a schematic illustration of a first embodiment of a thermostatconfigured to control operation based on percentage increase in energyprice rate in accordance with principles of the present disclosure;

FIG. 3 shows a second embodiment of a thermostat including a displaywhere the thermostat is configured to control operation based onpercentage increase in energy price rate in accordance with principlesof the present disclosure;

FIG. 4 shows the display of the thermostat in FIG. 3 including thedisplay of a setting menu;

FIG. 5 shows the display in FIG. 3 including a help screen;

FIG. 6 shows the display of the thermostat in FIG. 3 including thedisplay of a user selectable field in accordance with principles of thepresent disclosure; and

FIG. 7 is an illustration of another building incorporating athermostatic controller or thermostat according to the principles of thepresent disclosure, where the building further includes a ceiling fanand the thermostatic controller or thermostat is shown sending awireless signal to the ceiling fan.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

In various exemplary embodiments, a thermostatic controller comprises athermostat operable for curtailing air conditioner operation duringtimes when an energy price rate is relatively high. In other exemplaryembodiments, the thermostatic controller may be connected to additionalor different systems or energy consuming appliances such as shown inFIG. 1, e.g., an air conditioner system 22 for cooling a space 20, acontroller 26 for a water heater 24 (e.g., electric water heater, etc.),a spa water heater (not shown), a pool water heater (not shown), aceiling fan 30 (shown in FIG. 7), etc. In such examples, thethermostatic controller may be operable for curtailing operation of theheater or other energy consuming appliance during times when an energyprice rate is relatively high.

FIG. 1 illustrates an exemplary embodiment of a thermostatic controllerthat comprises a thermostat 100 for curtailing air conditioner operationwhen energy price rate is high. In this exemplary embodiment, thethermostat 100 is capable of sensing a temperature in a space 20 andcontrolling the operation of the air conditioner 22 to cool the space20. Accordingly, the thermostat 100 may comprise at least onetemperature responsive device that periodically outputs a valueindicative of the temperature in the space.

The sensor may be any of a number of sensor types, and may comprise acrystal, oscillator or other electronic device with a reactance orfrequency that changes in response to temperature. Alternatively, thesensor may comprise a thermistor having a resistance value that changesin response to changes in temperature. The sensor could also be a devicecapable of communicating a voltage value that correlates to, or isindicative of, the temperature sensed in the space. The sensor mayinclude circuitry to permit the sensor to communicate a value indicativeof the temperature that is accurate to a tenth of degree Fahrenheit. Thesensor may also include circuitry to enable communication of temperatureinformation on a periodic basis, or upon request, such as when promptedby a microprocessor of the thermostat 100. Accordingly, the at least onesensor is configured to sense and communicate information that isindicative of a temperature in the space 20. The thermostat 100 includesa microprocessor (shown as 130 in FIG. 2) and a program within themicroprocessor that utilizes a set point temperature, where themicroprocessor is configured to control operation of a thermostat and anair conditioner system 22 to adjust the sensed temperature in the space20 to maintain the set point temperature.

Referring to FIG. 2, the example thermostat 100 includes a receiverdevice 120 configured to receive a signal transmitted by a utility meter28 (FIG. 1) outside the space 20 that utilizes an Advanced MeteringInfrastructure (AMI) and receives signals from a utility provider thatcommunicate energy price rate information. Specifically, the utilitymeter 28 may periodically receive signals when a change occurs in energyprice rate for a given time period. For example, the utility metersignal may provide real-time energy price rates at intervals of 15minutes, for example. Different energy price rates may be utilizedduring various usage rate periods, such as a normal rate period, a lowrate period, a medium rate period, and a high rate period, for example.The utility provider could have a tiered structure with as many as 16energy price rates in a given day. Consequently, the energy price ratemay vary considerably from time to time.

The receiver device 120 is configured to receive, at least periodically,a signal wirelessly transmitted by the utility meter 28 that includesinformation of an energy price rate and/or a given time periodassociated with the price rate. The receiver device 120 is preferably incommunication with the microprocessor 130 of the thermostat 100, wherethe receiver device 120 and microprocessor 130 are connected to a lowvoltage power supply 122. The receiver device 120 is generally areceiver chip, which may also be connected to a resistor-capacitorfilter circuit 126 and an antenna 124.

The receiver device 120 is configured to receive a short range wirelesssignal transmitted by the utility meter 28 outside the space 20. Thereceiver device 120 receives a utility meter signal via the antenna 124,and may compare the signal to a reference signal. For example, thesignal may be compared to a local oscillator having a frequency of 418Megahertz (MHz), and then demodulated into a digital data stream. Thisdata may then be output via a Universal Asynchronous Serial transmission(UART) communication link, and is preferably decoded and transmitted asa serial bit stream signal from a data port pin of the receiver device120 to an input port pin (such as a UART Port) on the microprocessor130. The microprocessor 130 may be configured to load the signal datainto a software buffer for protocol verification, and configured tostrip the data and analyze a synchronization bit at the beginning of thesignal to synchronize the transmitted signal and the utility meter 28for identifying the unique serial number within the transmission toverify signal protocol with a serial number of a specific utility meter.When protocol verification of the transmitted signal is completed andthe signal for the utility meter 28 is verified, the microprocessor 130receives the data including information of a usage price rate, oralternatively a schedule of usage time periods and corresponding tieredenergy price rates. The microprocessor 130 stores the energy price rateinformation in an electronic memory 132, such as an EEPROM(electronically erasable programmable read only memory) memoryassociated with the microprocessor 130 but may alternatively store theinformation in a different type of memory and/or an electronic memoryexternal to the microprocessor 130.

In addition, the receiver device 120 may further comprise a transmitter,where the transmitter and receiver device 120 may be provided as asingle unit (e.g., a transceiver). Accordingly, the signal received bythe receiver device 120 includes energy price rate information, and thereceiver device 120 and electronic memory 132 are in communication withthe microprocessor 130 so as to permit one or more energy price rates tobe received and stored in the electronic memory 132.

As previously stated, the thermostat 100 includes a microprocessor 130that is programmable to control operation of at least an air conditionersystem to maintain a desired set point temperature. In this example, themicroprocessor 130 includes a memory (e.g., a read-only-memory, etc.)encoded with an instruction operable to select from one or more energyprice rates stored in the electronic memory 132 the lowest energy pricerate received in a given time period, for establishing a base energyprice rate. For example, the instruction may be configured to select thelowest energy price rate received within a 24 hour period, and toutilize the lowest price rate to establish a base energy price rate fora 24 hour period. The memory is further encoded with an instructionoperable to determine if the most recently received energy price ratefor the present time period exceeds the established base energy pricerate by more than a first percentage of the base energy price rate,where the first percentage is a user-selectable percentage. For example,the instruction may be operable to determine if an energy price rate of$0.20 per kilowatt-hour exceeds a base energy price rate of $0.12 perkilowatt-hour by more than 50 percent (an example of a selected firstpercentage) of the $0.12 per kilowatt-hour base price rate.

Accordingly, the microprocessor 130 is configured to detect an energyprice rate for the present time that exceeds the base energy price rateby more than a first percentage 134 (shown in FIG. 2), and to respond byselecting a first temperature offset 136 (shown in FIG. 2) correspondingto the first percentage 134, and incrementing the set point temperatureby the first temperature offset 136. Such an offset would result inincreasing the set point temperature above the sensed temperature of thespace to be cooled, so that the cooling requirement would be satisfiedand the air conditioner system would thereby remain off until the sensedtemperature rises above the increased set point temperature. Thus, thefirst percentage 134 and corresponding first temperature offset 136provide for reduced energy consumption and reduced energy costs whenenergy price rates are high. The first percentage 134 is preferably atleast 20 percent, and the first temperature offset 136 is preferablywithin the range of 1 to 20 degrees Fahrenheit.

The thermostat 100 may also provide the user with the capability ofoverriding a set point temperature that has been offset by the firsttemperature offset 136. If the user of the thermostat 100 occupying thespace prefers to lower the set point temperature for comfort reasons,the user may press a temperature up button 152 or a temperature downbutton 154 to adjust the current temperature setting (which may havebeen offset due to an increased price rate). This could effect atemporary override of a set point temperature that has been offset bythe first temperature offset 136. The temporary override would remain ineffect for a predetermined period of time, such as 2 hours, or until thenext usage rate period, for example. The microprocessor 130 may also beconfigured for two-way communication via the UART port, to transmit asignal via the transceiver/receiver device 120 notifying the utilityprovider of an override. The utility provider would then be made awareof the lack of reduction in energy consumption of a particular user.

The thermostat 100 may further include a display device 140 such as anliquid crystal display (LCD) device in communication with themicroprocessor 130, which is configured to display information such asthe current time and temperature setting, or the current usage energyprice rate period as normal, low, medium, or high. The display device140 is preferably configured to display the first percentage 134, toprovide for display of an easily discernible cost impact associated withan energy price rate that exceeds the base energy price rate by morethan the first percentage 134. The display device 140 is furtherconfigured to display the first percentage 134 and at least oneuser-selectable field for aiding the user in selecting a firsttemperature offset 136 for reducing energy costs when an energy pricerate exceeds the base energy price rate by the first percentage 134. Theat least one user-selectable field on the display device allows forinput of the user-selectable first percentage 134 and correspondinguser-selectable first temperature offset 136. The at least oneuser-selectable field on the display device 140 accordingly enables auser to select a threshold as a percentage 134 of the base energy pricerate at which the user desires the set point temperature to beincremented by the first temperature offset 136 for reducing energyconsumption to lower energy costs.

By displaying the first percentage 134 to provide an easily discerniblecost impact associated with an energy price rate that is more than thefirst percentage 134 above the base rate, the thermostat user would thenbe able to determine whether an override would affect the energy coststhat the user would be billed for. In this manner, the user would beable to determine how an override of the first temperature offset to theset point temperature would affect the user's energy costs, whereby thedisplay would cause the user to be less likely to override thetemperature offset to the set point temperature. Because the thermostat100 is configured to display a high energy price rate as a percentage ofa base energy price rate that is easily discernible, the user would beless likely to opt out or override the temperature offset to the setpoint temperature for reducing air conditioner operation. Accordingly,the thermostat 100 provides a utility provider with a reliable way tocurtail or reduce energy consumption using high energy price ratesduring a peak demand period (to keep energy demands within theirgenerating capacity during the peak period), and also provides a userwith a reliable way of controlling air conditioner operation during highenergy price periods to reduce the user's energy costs.

In addition to the above features, the receiver device 120 of thethermostat 100 may comprise a transceiver configured to transmitsignals. In which case, the microprocessor 130 may respond to an energyprice rate exceeding the base energy price rate by more than the firstpercentage by transmitting a signal via the transceiver to an energyconsuming appliance indicating that the appliance should be in an offstate. Conversely, the microprocessor 130 may respond to an energy pricerate that is below the base energy price rate, e.g., below by more thanthe first percentage, by transmitting a signal via the transceiver tothe energy consuming appliance indicating that the appliance should bein an on state. By way of example, the energy consuming appliance may bean electric water heater appliance. In this example, the microprocessor130 may respond to an energy price rate exceeding the base energy pricerate by more than the first percentage by transmitting an off commandvia the transceiver to an energy consuming electric water heaterappliance, to thereby further reduce energy costs. In this example, thethermostat 100 may also be referred to as a thermostatic controller asit is operable for controlling the operation of the water heater.

Referring to FIG. 3, a second embodiment of a thermostat 200 accordingto the present disclosure is shown. The thermostat 200 includes the samecomponents in the first thermostat embodiment shown in FIG. 2, inparticular, a receiver device 120 configured to receive a signaltransmitted by a utility meter 28 that includes energy price rateinformation, and an electronic memory 132 in communication with amicroprocessor 130 so as to permit one or more energy price rates to bereceived and stored in the electronic memory 132.

The second embodiment of a thermostat 200 includes the samemicroprocessor 130 in the first embodiment, which includes a memoryencoded with an instruction operable to select from one or more energyprice rates stored in the electronic memory 132 the lowest energy pricerate received in a given time period for establishing a base energyprice rate. The is further encoded with an instruction operable todetermine if the most recently received energy price rate for thepresent time period exceeds the base energy price rate by more than afirst percentage of the base energy price rate.

The thermostat 200 that includes the microprocessor 130 in FIG. 2 isconfigured to detect an energy price rate for the present time thatexceeds the base energy price rate by more than a first percentage ormultiplier factor 234 shown on display 240 in FIG. 3, and to respond byselecting a first temperature offset 236 corresponding to the firstpercentage or multiplier factor 234 and incrementing the set pointtemperature by the first temperature offset 236. Such an offset wouldresult in increasing the set point temperature above the sensedtemperature of the space, so that the cooling requirement would besatisfied and cause the air conditioner system to remain off until thesensed temperature rises above the increased set point temperature.Thus, the first percentage or multiplier factor 234 and correspondingfirst temperature offset 236 thereby reduce energy consumption andenergy costs when energy price rates are high. The first percentage ormultiplier factor 234 is preferably at least 20 percent over the baserate, and more preferably at least 50 percent. Similarly, the firsttemperature offset 236 is preferably in the range of 1 to 20 degreesFahrenheit.

In addition to the above curtailment feature, the second embodiment of athermostat 200 includes a memory (e.g., read-only-memory, etc.) that isfurther encoded with an instruction operable to determine if the energyprice rate for the present time period exceeds the base energy pricerate by more than a second percentage or multiplier factor 244, whereinthe microprocessor is configured to responsively select a secondtemperature offset 246 corresponding to the second percentage ormultiplier factor 244 and increment the set point temperature by thesecond temperature offset 246. The second percentage 244 is at least 50percent over the base rate (and more preferably at least 100 percent),and the second temperature offset 246 is preferably in the range ofbetween 2 to 20 degrees Fahrenheit. The second embodiment of athermostat 200 may further include a third percentage or multiplierfactor 254 and a corresponding third temperature offset 256 that areeach respectively greater than the second percentage or multiplierfactor 244 and second temperature offset 246.

The second embodiment of a thermostat 200 may also provide the user withthe capability of overriding an increased set point temperature that wasoffset by the first temperature offset 236, second temperature offset246, or any additional temperature offsets. If the user of thethermostat occupying the space prefers to lower the set pointtemperature for comfort reasons, the user may press a temperature up ordown buttons 252 to adjust the current temperature setting to a desiredlevel, which would effect a temporary override of the increased setpoint temperature offset by the first temperature offset 236 or otheradditional temperature offsets. The temporary override would remain ineffect for a predetermined period of time, such as 2 hours, or until thenext usage rate period.

The second embodiment of a thermostat 200 includes a display device 240such as an LCD display in communication with the microprocessor, whichis configured to display the first percentage or multiplier factor 234,to provide for display of an easily discernible cost impact associatedwith an energy price rate that exceeds the base energy price rate bymore than the first percentage or multiplier factor 234. The displaydevice 240 is further configured to display the first percentage ormultiplier factor 234 and at least one user-selectable field 242 foraiding the user in selecting a first temperature offset 236 for reducingenergy costs when an energy price rate exceeds the base energy pricerate by the first percentage or multiplier factor 234. The at least oneuser-selectable field 242 on the display device allows for input of theuser-selectable first percentage or multiplier factor 234 andcorresponding user-selectable first temperature offset 236. Theuser-selectable fields 242 on the display device 240 accordingly enablea user to select a threshold as a percentage or multiplier factor 234 ofthe base energy price rate at which the user desires the set pointtemperature to be incremented by one or more temperature offsets 236,246 and 256 for reducing energy consumption to lower energy costs.

By displaying the first percentage or multiplier factor 234 to providean easily discernible cost impact associated with an energy price ratethat is more than the first percentage 234 above the base rate, thethermostat user would then be able to determine whether an overridewould affect the energy costs that the user would be billed for. In thismanner, the user would be able to determine how an override of the firsttemperature offset to the set point temperature would affect the user'senergy costs, whereby the display would cause the user to be less likelyto override the temperature offset to the set point temperature. Becausethe thermostat 200 is configured to display a high energy price rate asa percentage or multiplier factor of a base energy price rate that iseasily discernible, the user would be less likely to opt out or overridethe temperature offset to the set point temperature for reducing airconditioner operation. Accordingly, the thermostat 100 provides autility provider with a reliable way to curtail or reduce energyconsumption using high energy price rates during a peak demand period(to keep energy demands within their generating capacity during the peakperiod), and also provides a user with a reliable way of controlling airconditioner operation during high energy price periods to reduce theuser's energy costs.

The thermostat 200 may further be configured to control operation of oneor more energy consuming appliances such as an electric water heater 24,a pool water heater, a spa water heater, one or more ceiling fans, etc.With control of such appliances, the thermostat 200 can listen to theenergy price rate signals from the utility meter and automatically turnoff energy consuming devices when user defined percentages or pricethresholds have been surpassed. The receiver device preferably comprisesa transceiver configured to receive and transmit signals. And, themicroprocessor is configured to respond to an energy price rate thatexceeds the base energy price rate by more than the first percentage ormultiplier factor by transmitting an off command via thetransceiver/receiver device to an energy consuming electric water heaterappliance, to thereby reduce energy costs. Conversely, themicroprocessor may be configured to respond to an energy price rate thatis below the base energy price rate, e.g., below by more than the firstpercentage, by transmitting an on command via the transceiver to theenergy consuming electric water heater. In this example, the thermostat200 may also be referred to as a thermostatic controller as it isoperable for controlling the operation of the water heater.

Alternatively, the thermostat 200 may further be configured to include aconnection with a contactor 26 that the thermostat 200 can switch on andoff to connect or disconnect the supply of power to an electric waterheater 24, to thereby control the operation of the water heater 24. Thethermostat 200 may be similarly connected to a second contactor forcontrolling power to a pool water heater, spa water heater, one or moreceiling fans, etc. in the same manner. In this manner, the thermostat200 can control the operating level of one or more energy consumingappliances or systems. The thermostat 200 is not required to beconnected to such systems, however, and may operate independent of aconnection to such systems.

The applicants have found through research that the energy price rateper kilowatt-hour has little psychological impact on consumers as ametric unto itself. Most homeowners cannot infer what a rate of $0.12per kilowatt-hour versus a rate of $0.14 per kilowatt-hour wouldtranslate to in terms of their monthly energy bill. The applicants havedeveloped an approach for automated price response which is predicatedon the delta or percentage difference from a base energy price rate, asthis information is more easily discerned by consumers. The approachutilized by the thermostatic controller embodiments of the presentdisclosure enable consumers to set their price thresholds in terms of apercent increase, or multiple, over a base energy price rate, where thebase energy price rate is defined as the lowest rate in the last 24 hourperiod.

Referring to FIG. 4, the thermostat 200 receives variable energy pricerate signals from the AMI utility meter that the thermostat 200 willlisten to and respond to automatically, to maximize the effectiveness ofprice/demand response. The price threshold feature of the thermostat 200enables the user to program how to respond to the price signals. Thethermostat 200 includes user input buttons, such as arrows 252, that theuser may use to turn price thresholds ‘On,’ which may prompt the displayof an arrow icon to the right of the word ‘On,’ as shown in FIG. 4. Theuser may also select a ‘Help’ icon that will prompt the display of ahelp screen as shown in FIG. 5, which includes information to help theuser to understand the process. The user utilizes inputs 252 to move upor down through the menu options one at a time, and the right arrow willtake the user to the set up screen for the selected menu option, whichmay be for input of the first percentage or multiplier factor and firsttemperature offset as shown in FIG. 6.

Referring to FIGS. 3-6, once the user has set the price thresholds to‘On’ via the input buttons 252, the thermostat 200 is configured todisplay a threshold screen that includes the display of the firstpercentage or multiplier factor 234, second percentage or multiplierfactor 244, and third percentage or multiplier factor 254, and theircorresponding first temperature offset 236, second temperature offset246, and third temperature offset 256. The thermostat 200 will obtainthe lowest energy price rate received in the last 24 hours, and maydisplay this rate as the base energy rate. The user of the thermostat200 may utilize the input buttons 252 to scroll through the user inputfields 242 to allow the user/homeowner to set the first, second, orthird percentages or multiplier factors 234, 244, and 254, which serveas threshold or trigger points for incrementing the set pointtemperature by the corresponding temperature offsets 236, 246, and 256.

In addition, the display device 240 displays one or more commandsassociated with energy consuming device 1, energy consuming device 2,and energy consuming device 3. This allows the user to set thresholdsfor automatically switching on and off an electric water heater 24, forexample, to reduce the operation of the water heater 24. In this manner,the thermostat 200 can control the operating level of one or more energyconsuming appliances or systems, to further reduce energy costs duringhigh energy price rate periods.

As described above, FIGS. 2 and 3 show first and second exemplaryembodiments of thermostat 100, 200, respectively, that may be operablefor controlling operation of a heating ventilation and air-conditioning(HVAC) system, e.g., that includes air conditioner system 22, etc. Theseillustrated thermostats 100, 200 are two examples of a controller thatare usable in accordance with principles of the present disclosure forload reduction based on percentage change in energy price. Othercontrollers may also be used in other embodiments, including otherthermostats and other thermostatic controllers operable for controllinga wide range of energy consuming appliances. For example, otherexemplary embodiments may include a thermostatic controller that isoperable as a control for a water heater (e.g., electronic water heater,etc.), pool water heater, spa water heater, one or more ceiling fans,etc. whereby the thermostatic controller is operable for curtailing loadof the heater or ceiling fan when energy price rate is high.Accordingly, aspects of the present disclosure should not be limitedsolely to thermostats or to just curtailment of air conditioner load.

In an exemplary embodiment, there is a thermostatic controller operableas a control for a water heater. In this example, the thermostaticcontroller is operable for curtailing the load of the water heater whenenergy price rate is high. The thermostatic controller includes areceiver device, a memory, and a microprocessor. The receiver device isconfigured to receive a signal that includes an energy price rate for agiven time period. One or more energy price rates received by thereceiver device are stored in the memory. The microprocessor isconfigured to control operation of the water heater to maintain a setpoint temperature of the water that is heated by the water heater. Themicroprocessor is configured to select from the lowest energy price ratereceived within a given time period for establishing a base energy pricerate, and also to determine if the energy price rate for a present timeperiod exceeds the base energy price rate by more than a firstpercentage of the base energy price rate. The microprocessor is furtherconfigured to respond to an energy price rate that exceeds the baseenergy price rate by more than the first percentage by selecting a firsttemperature offset corresponding to the first percentage and decreasingthe set point temperature by the first temperature offset. The decreasedset point temperature of the water to be heated would curtail or reducethe operation of the heater and reduce energy costs during high energyprice rate periods.

In another exemplary embodiment, there is a thermostatic controller,e.g., a wireless thermostat, etc. that is also operable for curtailingload of one or more ceiling fans. In this example, the thermostaticcontroller includes a transceiver configured to receive a signal thatincludes an energy price rate for a given time period and an electronicmemory device in which one or more energy price rates received by thetransceiver are stored. A microprocessor is in communication with thetransceiver and electronic memory. The microprocessor configured toselect from the one or more energy price rates the lowest energy pricerate received within a given time period for establishing a base energyprice rate; determine if the energy price rate for a present time periodexceeds the base energy price rate by more than a first percentage ofthe base energy price rate; and respond to an energy price rate thatexceeds the base energy price rate by more than the first percentage bytransmitting a signal via the transceiver to one or more ceiling fans toactivate, deactivate and/or change speed of the one or more ceilingfans. Accordingly, the thermostatic controller is operable to activate,deactivate, and/or change speed of the one or more ceiling fans as afunction of a base energy price rate increase.

By way of example, the thermostatic controller may be configured torespond to an energy price rate that exceeds the base energy price rateby more than the first percentage (e.g., 50%, etc.) by transmitting asignal via the transceiver to the one or more ceiling fans indicatingthat the one or more ceiling fans should be operating at a low speed. Ifthe energy price rate exceeds the base energy price rate by more than asecond percentage (e.g., 100%, etc.), which is higher than the firstpercentage, a signal may be transmitted via the transceiver to the oneor more ceiling fans indicating that the one or more ceiling fans shouldbe operating at a medium speed which is higher than the low speed. And,if the energy price rate exceeds the base energy price rate by more thana third percentage (e.g., 150%, etc.), which is higher than the secondpercentage, a signal may be transmitted via the transceiver to the oneor more ceiling fans indicating that the one or more ceiling fans shouldbe operating at a high speed which is higher than the medium speed.

FIG. 7 is an illustration of another building incorporating athermostatic controller or thermostat 100 according to the principles ofthe present disclosure, where the building further includes a ceilingfan 30 and the thermostatic controller or thermostat 100 is shownsending a wireless signal to the ceiling fan 30. Also shown in FIG. 7are an air conditioner system 22 for cooling a space 20, a water heater24 having a controller 26, and a utility meter 28 as described above.

With further regard to FIG. 7, the thermostatic controller 100 isoperable for switching on/off the ceiling fan 30 as a function of thetier rate. In this example, the thermostat user could select to have thethermostat turn on the ceiling fan 30 via one of the device settings asshown in FIG. 3, for example. The user could select to have thethermostat 100 communicate an ON signal to a device “ceiling fan—device1” if the setback as a function of the rate increase was 3° or greater,etc. The user could also select to have the ceiling fan come on for allthree setback temperatures, connected to base rate increases, or anycombination of the three. The communication between the thermostat 100and ceiling fan 30 may preferably be wireless as shown in FIG. 7, whichwireless method may be based on Bluetooth, Z-wave, or other comparableprotocol.

In addition, there may be more than one ceiling fan in the conditionedspace 20. In such example, and with reference to FIG. 3, Device 1 mayperhaps be a ceiling fan in the kitchen, Device 2 may be a ceiling fanin the living room, and Device 3 may be a ceiling fan in a bedroom, forexample. The user could select which fans to turn ON or OFF as afunction of the location of the given fan, as a function of the chosensetback, invoked by the select rate increase.

In addition, the thermostat may communicate a signal indicative of thefan speed as a function of the temperature setback invoked by the rateincrease. For example, referring to FIG. 3, a rate increase of 50% willcause the thermostat to communicate a Low Speed ON signal to Device 1,which is a ceiling fan in this example. A rate increase of 100% willcause the thermostat (or thermostatic controller) to communicate aMedium Speed ON signal to the Device 1 ceiling fan. And, a rate increaseof 150% will cause the thermostatic controller to communicate a HighSpeed ON signal to the Device 1 ceiling fan. Accordingly, aspects of thepresent disclosure include thermostatic controllers able to activate,deactivate, and/or change one or more speeds of one or more ceiling fansas a function of a base rate increase.

Various exemplary embodiments of a controller for a variable outputheating apparatus are provided, which may be connected to either asingle stage or a two-stage thermostat. An exemplary embodiment of athermostat includes a receiver device configured to receive a signalincluding energy price rate information. The thermostat also includes anelectronic memory device in which one or more energy price ratesreceived by the receiver device are stored. The thermostat furtherincludes a microprocessor in communication with the receiver device andelectronic memory. The microprocessor is configured to control operationof an air conditioner system to maintain a set point temperature for aspace. The microprocessor includes a memory encoded with an instructionoperable to select from the one or more energy price rates the lowestenergy price rate received within a given time period for establishing abase energy price rate, and further encoded with an instruction operableto determine if the energy price rate for a present time period exceedsthe base energy price rate by more than a first percentage of the baseenergy price rate. The microprocessor is configured to respond to anenergy price rate that exceeds the base energy price rate by more thanthe first percentage by selecting a first temperature offsetcorresponding to the first percentage and increasing the set pointtemperature by the first temperature offset, whereby the increased setpoint temperature reduces energy consumption when an energy price rateis significantly higher than the base energy price rate.

In an exemplary embodiment, there is a thermostat capable of receivingsignals transmitted by a utility provider communicating a usage rateschedule or a request for a load curtailment period, and controlling oneor more systems based on the information communicated by the utilityprovider. In this example, the thermostat changes the set point for eachsystem to the stored predetermined control set point corresponding tothe current usage rate schedule period or the curtailment mode periodwhen requested. Also in this example, the thermostat is further capableof discontinuing operation of one or more systems for a minimumpredetermined time period following a request for a load curtailmentperiod.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the invention. Individual elements or features ofa particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the invention, and all such modificationsare intended to be included within the scope of the invention.

Example embodiments are provided so that this disclosure will bethorough, and will fully convey the scope to those who are skilled inthe art. Numerous specific details are set forth such as examples ofspecific components, devices, and methods, to provide a thoroughunderstanding of embodiments of the present disclosure. It will beapparent to those skilled in the art that specific details need not beemployed, that example embodiments may be embodied in many differentforms and that neither should be construed to limit the scope of thedisclosure. In some example embodiments, well-known processes,well-known device structures, and well-known technologies are notdescribed in detail.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a,” “an,” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “including,” and“having,” are inclusive and therefore specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. The method steps, processes, and operations described hereinare not to be construed as necessarily requiring their performance inthe particular order discussed or illustrated, unless specificallyidentified as an order of performance. It is also to be understood thatadditional or alternative steps may be employed.

When an element or layer is referred to as being “on,” “engaged to,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, engaged, connected or coupled to the other element orlayer, or intervening elements or layers may be present. In contrast,when an element is referred to as being “directly on,” “directly engagedto,” “directly connected to,” or “directly coupled to” another elementor layer, there may be no intervening elements or layers present. Otherwords used to describe the relationship between elements should beinterpreted in a like fashion (e.g., “between” versus “directlybetween,” “adjacent” versus “directly adjacent,” etc.). As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items.

Although the terms first, second, third, etc. may be used herein todescribe various elements, components, regions, layers and/or sections,these elements, components, regions, layers and/or sections should notbe limited by these terms. These terms may be only used to distinguishone element, component, region, layer or section from another region,layer or section. Terms such as “first,” “second,” and other numericalterms when used herein do not imply a sequence or order unless clearlyindicated by the context. Thus, a first element, component, region,layer or section discussed below could be termed a second element,component, region, layer or section without departing from the teachingsof the example embodiments.

Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,”“lower,” “above,” “upper,” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. Spatiallyrelative terms may be intended to encompass different orientations ofthe device in use or operation in addition to the orientation depictedin the figures. For example, if the device in the figures is turnedover, elements described as “below” or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.Thus, the example term “below” can encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

What is claimed is:
 1. A thermostatic controller for curtailing load of one or more energy consuming appliances when energy price rate is high, the thermostatic controller comprising: a receiver device configured to receive a signal that includes an energy price rate for a given time period; an electronic memory device in which one or more energy price rates received by the receiver device are stored; and a microprocessor in communication with the receiver device and electronic memory, the microprocessor configured to control operation of an energy consuming appliance to maintain a set point temperature, the microprocessor including a memory encoded with an instruction operable to select from the one or more energy price rates the lowest energy price rate received within a given time period for establishing a base energy price rate, and further encoded with an instruction operable to determine if the energy price rate for a present time period exceeds the base energy price rate by more than a first percentage or multiplier factor of the base energy price rate; wherein the microprocessor is configured to respond to an energy price rate that exceeds the base energy price rate by more than the first percentage or multiplier factor by selecting a first temperature offset corresponding to the first percentage or multiplier factor and changing the set point temperature by the first temperature offset.
 2. The thermostatic controller of claim 1, wherein the microprocessor is operable to select the lowest energy price rate received within a 24 hour period, which lowest energy price rate is utilized to establish the base energy price rate.
 3. The thermostatic controller of claim 1, wherein the first percentage or multiplier factor is a user-selectable percentage that is selectable as a value of at least 20 percent or a user-selectable multiplier factor that is selectable as a value of at least 1.5.
 4. The thermostatic controller of claim 1, wherein the first temperature offset is a user-selectable temperature offset selectable from a range of between 1 degree Fahrenheit to 20 degrees Fahrenheit; and/or whereby the changed set point temperature reduces energy consumption when an energy price rate is significantly higher than the base energy price rate.
 5. The thermostatic controller of claim 1, further comprising a display device that is configured to display user-selectable fields for input of a user-selectable percentage or user-selectable multiplier factor, and corresponding user-selectable temperature offset, to enable a user to select a threshold as a percentage or multiplier factor of the base energy price rate at which the user desires the set point temperature to be adjusted by the first temperature offset for reducing energy consumption to lower energy costs.
 6. The thermostatic controller of claim 1, further comprising a display device configured to display the first percentage or multiplier factor, to provide for display of an easily discernible cost impact associated with an energy price rate that exceeds the base energy price rate by more than the first percentage or multiplier factor.
 7. The thermostatic controller of claim 6, wherein the display device is further configured to display the first percentage or multiplier factor and a user-selectable field for aiding the user in selecting the first temperature offset for reducing energy costs when an energy price rate exceeds the base energy price rate by the first percentage or multiplier factor.
 8. The thermostatic controller of claim 1, wherein: the memory of the microprocessor is further encoded with an instruction operable to determine if the energy price rate for the present time period exceeds the base energy price rate by more than a second percentage or multiplier factor; and the microprocessor is configured to responsively select a second temperature offset and adjust the set point temperature by the second temperature offset.
 9. The thermostatic controller of claim 8, wherein: the second percentage or multiplier factor is a user-selectable percentage that is a value of at least 50 percent or a user-selectable multiplier factor of at least 1.5; and the second temperature offset is a user-selectable temperature offset selectable from a range of between 2 degrees Fahrenheit to 20 degrees Fahrenheit.
 10. The thermostatic controller of claim 1, wherein the receiver device is configured to receive a wireless signal including the energy price rate information that is transmitted by a utility meter.
 11. The thermostatic controller of claim 1, wherein: the receiver device comprises a transceiver configured to receive and transmit signals; and the microprocessor is configured to respond to an energy price rate that exceeds the base energy price rate by more than the first percentage or multiplier factor by transmitting an off command via the transceiver to an energy consuming appliance.
 12. The thermostatic controller of claim 1, wherein: the receiver device comprises a transceiver configured to receive and transmit signals; and the microprocessor is configured to respond to an energy price rate that exceeds the base energy price rate by more than the first percentage or multiplier factor by transmitting a signal via the transceiver to an energy consuming appliance indicating that the energy consuming appliance should be in an off state.
 13. The thermostatic controller of claim 12, wherein the microprocessor is configured to respond to an energy price rate that is below the base energy price rate by more than the first percentage or multiplier factor by transmitting a signal via the transceiver to an energy consuming appliance indicating that the energy consuming appliance should be in an on state.
 14. The thermostatic controller of claim 1, wherein the thermostatic controller comprises: a thermostat for controlling operation of one or more energy consuming appliances of a heating ventilation and air-conditioning (HVAC) system; and/or a control for a water heater; and/or a control for a pool water heater; and/or a control for a spa water heater; and/or a control for a ceiling fan.
 15. The thermostatic controller of claim 1, wherein: the thermostatic controller comprises a control for a water heater; the microprocessor is configured to control operation of the water heater to maintain a set point temperature of water heated by the water heater; and the microprocessor is configured to respond to an energy price rate that exceeds the base energy price rate by more than the first percentage or multiplier factor by selecting a first temperature offset corresponding to the first percentage or multiplier factor and decreasing the set point temperature by the first temperature offset.
 16. The thermostatic controller of claim 1, wherein the thermostatic controller includes a connection with a contactor by which the thermostatic controller can switch on and off to connect or disconnect a supply of power to the energy consuming appliance, to thereby control operation of the energy consuming appliance.
 17. A method of using a thermostatic controller to curtail load when energy price rate is high, the method comprising: receiving a signal that includes an energy price rate for a given time period; storing one or more energy price rates in an electronic memory; selecting a lowest energy price rate received within a given period of time from the one or more energy price rates stored in the electronic memory by using a microprocessor in communication with the electronic memory, for establishing a base energy price rate; determining, using the microprocessor, if the energy price rate for a present time period exceeds the base energy price rate by more than a first percentage or multiplier factor of the base energy price rate; and responding to an energy price rate that exceeds the base energy price rate by more than the first percentage or multiplier factor by selecting, using the microprocessor, a first temperature offset corresponding to the first percentage or multiplier factor and adjusting a set point temperature of an energy consuming appliance by the first temperature offset to thereby reduce energy consumption.
 18. The method of claim 17, wherein the energy consuming appliance comprises a water heater, and the method includes using the microprocessor to decrease the set point temperature of the water heater by the first temperature offset to thereby reduce energy consumption. 